摘要:

AbstractVarious synthetic esters were tested for their biodegradability, using a test sequence that began with the creation of biomass using sucrose and municipal wastewater; biodegradation was measured using biochemical oxygen demand and chemical oxygen demand values. The test esters and resulting extractable matter were analysed by spectrophotomety. The esters were found to be biodegradable, to different degrees, subject to the presence of large amounts of water and the correct saline nutritive substratum.

ISSN:0265-6582    

DOI:10.1002/jsl.3000040102

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractThis paper reviews the development of aviation turbine lubricants from the early days of jet propulsion and projects it through to the end of this century. Up to the present period, ester‐based synthetic oils have predominated, and largely fulfilled service requirements. However, ester‐based ‘Type 2’ lubricants are now perceived to be close to their optimum performance level and a new lubricant type will be required for the next generation of engines. The development of a ‘Type 3’ oil presents a great challenge to the aviation industry and could signal a departure from traditional routes of lubricant

ISSN:0265-6582    

DOI:10.1002/jsl.3000040103

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractExperience with existing oils used in helicopters for transmissions, engines, hydraulics and brakes has shown that three main characteristics could drastically improve the performance of the aircraft.These characteristics are: (1) the same type of oil should be usable for all the above mentioned systems; (2) the oil brands, produced to a common specification, but by different manufacturers, should be mixable without restrictions; (3) some features of the oil, which are specially important for helicopter operations, should be improved. Tests on mixed oils are reported, and recommendations made for future specifications.

ISSN:0265-6582    

DOI:10.1002/jsl.3000040104

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractEfficiency tests were conducted using eleven different lubricants in the NASA Lewis Research Center's 500 hp torque regenerative helicopter transmission test stand. The test transmission was the OH58A helicopter main transmission. The mechanical power input to the test transmission was 224 kW (300 hp) at 6060 r/min. Tests were run at oil‐in temperatures of 335°K (180°F) and 372°K (210°F). The efficiency was calculated from a heat balance on the water running through an oil‐to‐water heat exchanger while the transmission was heavily insulated. The test lubricants were analysed for their physical and chemical properties. Data on pressure‐viscosity characteristics as well as friction data from LFW‐1 type testing were examined for possible correlation with the efficiency data.The following results were obtained. (1) Among the eleven different lubricants, the efficiency ranged from 98.3 to 98.8%, which is a 50% variation relative to the losses associated with the maximum efficiency measured. (2) for a given lubricant, the efficiency increased as temperature increased and thus as viscosity decreased. There were two exceptions which could not be explained on the basis of available data. (3) There was a reasonable correlation of efficiency with absolute viscosity (corrected for temperature and pressure in the contact). (4) Between lubricants, efficiency did not correlate well with absolute viscosity at atmospheric pressure. (5) Between lubricants, efficiency did not correlate well with calculated lubricant film forming capacity. (6) Bench type (LFW‐1) sliding friction and wear measurements could not be correlated to transmission efficiency and component wear. (7) The lubricants had no significant effect on the vibration signature of t

ISSN:0265-6582    

DOI:10.1002/jsl.3000040105

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

ISSN:0265-6582    

DOI:10.1002/jsl.3000040106

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

ISSN:0265-6582    

DOI:10.1002/jsl.3000040107

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

ISSN:0265-6582    

DOI:10.1002/jsl.3000040108

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

ISSN:0265-6582    

DOI:10.1002/jsl.3000040109

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

ISSN:0265-6582    

DOI:10.1002/jsl.3000040101

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY